1. Field of the Invention
The present invention relates to the field of compressors, more particularly, to tools and fittings specifically designed and adapted for facilitating the task of changing the oil in a compressor having a crankcase which contains both a lubricating oil and a refrigerant, for example, a chlorofluorocarbon, also referred to as a "CFC".
2. Description of the Related Art
U.S. Pat. No. 4,977,978 relates to an oil change apparatus for use in changing the oil in a motor vehicle that includes a key operated drain valve removably mounted within a lockable protective housing and a flexible line connecting the drain valve with the engine oil pan of the motor vehicle.
U.S. Pat. No. 4,951,723 relates to a motorcycle engine oil drain plug that includes a tube that threads into the drain hole of the engine, a port provided in the tube, and a piston that is movable to cover and uncover the port.
U.S. Pat. No. 4,745,894 relates to an oil drain fitting for internal combustion engines that includes a body threaded into the conventional oil pan drain hole with an axial passage having a tubular valve reciprocally mounted therein.
U.S. Pat. No. 4,338,793 relates to an adapter for connection to an original equipment "Schrader" valve commonly found in closed refrigeration systems, the adapter including a duplicate "Schrader" valve that is oriented perpendicularly to the original equipment "Schrader" valve and is thus more easily accessible.
U.S. Pat. No. 3,996,765 relates to a device for removing or adding fluid refrigerant to a closed refrigerant system that includes a body having a passageway therethrough provided at its respective ends with threaded members for connecting the device to an access valve of the refrigerant system and to a refrigerant charging hose.